• 제목/요약/키워드: Fe-Si alloy

검색결과 412건 처리시간 0.051초

Fe-Si-C 합금의 합금화 과정에 따른 구조 및 자기적 특성 변화 연구 (Structural and Magnetic Properties of Fe-Si-C Alloys with Processing Times)

  • 유용구;김태엽;김약연;한기평;유성초;양동석
    • 한국자기학회지
    • /
    • 제12권5호
    • /
    • pp.179-183
    • /
    • 2002
  • 기계적 합금화 방법을 통하여 Fe-Si-C계 합금을 제조하였으며, 합금화 과정에 따른 구조 및 자기적 특성을 분석하였다 구조적 특성의 분석은 X-선 회절 실험과 EXAFS(extended X-ray absorption fine structure)실험을 통하여 수행하였고, 자기적 특성은 시료진동형자력계와 M ssbauer 분광법으로 연구하였다. 합금화 시간이 증가함에 따라 Si, C 원자들은 Fe 구조 속으로 확산되었으며, 12시간 이후로는 과포화된 bcc 고용체를 형성하였다. 합금화 시간에 따른 포화 자화값 및 초미세 자기장은 4시간까지 급격한 감소를 나타내었으며, 그 이후로는 완만한 감소를 나타내었고, 12시간 이후로는 변화가 적음을 나타내었다. 이러한 변화는 구조 특성 분석 결과와 일치하였다.

Fe기 MA956 산화물분산강화합금의 천이액상확산접합에 관한 연구 (Transient-Liquid-Phase Bonding of Fe-Base MA956 ODS Alloy)

  • 강지훈
    • 한국분말재료학회지
    • /
    • 제2권1호
    • /
    • pp.53-62
    • /
    • 1995
  • TLP(Transient-Liquid-Phase) bonding of Fe-base MA956 ODS alloy was performed. As insert metal a commercially available Ni-base alloy(MBF50) and an MA956 alloy with additive elements of 7wt% Si and 1wt% B were used. To confirm the idea that a concurrent use of MA956 powder with Insert metals can enhance the homogenization of constituent elements and thereby reduce the thickness of joint interface, MA956 powder was also inserted In a form of sheet. SEM observation and EDS analysis revealed that Cr-rich phase was formed in the bonded interface in initial stage of isothermal solidification during the bonding process, irrespective of kind of insert metals. Measurement of hardeness in the region of bonded interface and EDS analysis showed that a complete homogenization of composition could not be obtained especially in case of MBF50. Joints using either BSi insert metals only or BSi insert together with MA956 powder interlayer showed, however, a remarkable improvement in a compositional homogenization, even though a rapid grain growth in the bonded interface could not be hindered.

  • PDF

전자기력을 이용한 Al scrap으로 부터 과공정 Al-Si합금의 제조 (Manufacturing Al-scrap into Hypereutectic Al-Si Alloy by Using Electromagnetic Force)

  • 윤지현;문광호;김용현;이광학
    • 한국주조공학회지
    • /
    • 제21권6호
    • /
    • pp.328-335
    • /
    • 2001
  • The objective of this study is to investigate on manufacturing Al-scrap into hypereutectic Al-Si alloy by using electromagnetic force. The Fe element in the aluminium scrap was controlled by intermetallic compound method and using EMF(electromagnetic force). The most lumped compound was found after 10min holding at $690^{\circ}C$. A number of segregated compound was revealed when imposed to EMF at 30A. The refinement of primary Si particles was achieved by EMF stirring. Primary Si particles were refined and spheroidized most of all with the magnetic intensity of 180G for 10 min.

  • PDF

자동차 경량소재 AlSiCu 합금의 기계적 특성을 개선하기 위한 최적의 이중 열처리공정 (Optimal Double Heat Treatment Process to Improve the Mechanical Properties of Lightweight AlSiCu Alloy)

  • 박상규;김정석
    • 한국기계가공학회지
    • /
    • 제17권3호
    • /
    • pp.102-108
    • /
    • 2018
  • The objective of this study is to develop the mechanical properties of an AlSiCu aluminum alloy using the two-step solution heat treatment. The microstructure of the gravity casting specimen represents a typical dendrite structure with a secondary dendrite arm spacing (SDAS) of 40 um. In addition to the Al matrix, a large amount of coarsen eutectic Si phase, $Al_2Cu$ intermetallic phase, and Fe-rich phases is generated. The eutectic Si phases are fragmented and globularized with the solution heat treatment. The $Al_2Cu$ intermetallic phase is also resolutionized into the Al matrix. The $2^{nd}$ solution temperature at $525^{\circ}C$ may be an optimal condition to enhance the mechanical properties of the AlSiCu aluminum alloy.